In general, a small-sized hydraulic excavator called a mini-excavator is used suitably for an excavating operation in a narrow working site such as urban areas. Since this small-sized hydraulic excavator is used for a demolition work in the inside of a building or an excavating operation in a narrow area of a street, a machine weight thereof is set to approximately 0.8 to 4 tons, for example. In such small-sized hydraulic excavator, a foot range in which an operator puts the foot on an upper revolving structure is designed to be small.
Here, the small-sized hydraulic excavator is configured of an automotive lower traveling structure, an upper revolving structure that is supported through a revolving device on the lower traveling structure, and a front device that is tiltably mounted in the front side of the upper revolving structure. The small-sized hydraulic excavator is configured in such a manner that the upper revolving structure does not interfere with obstacles in the circumference upon operating/revolving the upper revolving structure in the narrow working site. That is, the small-sized hydraulic excavator is configured in such a manner that at least the rear side of the upper revolving structure (outer peripheral surface of a counterweight) can revolve within a vehicle width of the lower traveling structure to a vehicle width dimension of the lower traveling structure (width dimension between left and right drive devices).
The upper revolving structure has a revolving frame that is formed as a support structure, and a counterweight is mounted in the rear side of the revolving frame for acting as a weight balance to the front device. In addition, an engine is mounted in the front side to the counterweight on the revolving frame in a horizontal state of extending in the left-right direction, and a hydraulic pump is driven by the engine.
In the small-sized hydraulic excavator, various types of equipment is arranged in a limited installation space on the small revolving frame. An operator's seat stand is provided on the revolving frame to cover an upper side of the engine, and an operator's seat is mounted on the operator's seat stand. Further, a floor member is provided in front of the operator's seat stand to extend in the left-right direction on the revolving frame. The floor member is a place on which an operator who has sat on the operator's seat puts the feet, and the left side of the floor member is an entrance way to the operator's seat.
A pilot valve and an operating pedal are provided in a front position of the floor member, wherein the pilot valve controls supply/discharge of a pilot pressure to a control valve device and the operating pedal is provided in the pilot valve and is foot-operated in the upper-lower direction by an operator.
Here, the floor member of the small-sized hydraulic excavator has a narrow space surrounded by the engine, an oil reservoir tank and the front device. Therefore, the operating pedal provided in the front position of the floor member is configured to be capable of being folded in such a manner as not to occupy a space at non-use (Patent Document 1).